from django.shortcuts import render
from .models import Post
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.shortcuts import render, get_object_or_404
from .forms import EmailPostForm, CommentForm
from django.core.mail import send_mail
from taggit.models import Tag
# 导入Django聚合函数Count
from django.db.models import Count
from django.contrib.postgres.search import SearchVector
from .forms import EmailPostForm, CommentForm, SearchForm



def post_detail(request, year, month, day, post):
    post = get_object_or_404(Post, slug=post, status='published', 
                          publish__year=year, 
                          publish__month=month, 
                          publish__day=day)
     # 找到所有相似文章
# 找到当前文章的标签编号 
    post_tags_ids = post.tags.values_list('id', flat=True) 
# 找到包含当前文章任意标签的文章集合（除当前文章外） 
    similar_posts = Post.published.filter(tags__in=post_tags_ids)\
    .exclude(id=post.id) 
# 对相似文章按照相同标签数量进行排序，取前4个，相同标签数量使用聚合函数Count
 # 计算后保存在same_tags中，以便后续使用 
    similar_posts = similar_posts.annotate(same_tags=Count('tags'))\
    .order_by('-same_tags','-publish')[:4]
    # 获取数据库中当前文章的所有评论中状态为可以查看的评论 
    comments = post.comments.filter(active=True)
    new_comment = None
    # 如果请求类型是POST，则获取请求中的评论数据构建评论并保存到数据库 
    if request.method == 'POST': 
# 获取请求中的评论数据构建评论表单 
        comment_form = CommentForm(data=request.POST) 
# 如果通过表单有效性校验则构建评论数据并保存 
        if comment_form.is_valid(): 
            new_comment = comment_form.save(commit=False) 
            new_comment.post = post 
            new_comment.save() 
    else: 
# 如果请求类型不是POST，则构建空评论表单 
        comment_form = CommentForm()

    return render(request,'blog/post/detail.html', {'post': post,'comments': comments, 
'new_comment': new_comment,'comment_form': comment_form, 'similar_posts': similar_posts})
def post_list(request, tag_slug=None): 
  posts = Post.published.all()
  # 创建变量tag，用于存储下方代码获取的标签 
  tag = None 
# 如果请求中有tag_slug，则获取标签并按标签过滤文章数据 
  if tag_slug: 
# 获取标签 
        tag = get_object_or_404(Tag, slug=tag_slug) 
# 按标签过滤文章 
        posts = posts.filter(tags=tag)
  paginator = Paginator(posts, 3)
  page = request.GET.get('page')
  try:
    posts = paginator.page(page)
  except PageNotAnInteger:
      posts = paginator.page(1)
  except EmptyPage:
        posts = paginator.page(paginator.num_pages)
  return render(request,'blog/post/list.html',{'posts': posts,'page': page, 'tag': tag})
def post_share(request, post_id): 
  return render(request, 'blog/post/share.html')

def post_share(request, post_id): 
# 获取要分享的文章信息 
  post = get_object_or_404(Post, id=post_id, status='published') 
# 设置发送状态为未发送 
  sent = False 
# 如果请求是POST表示有提交表单 
  if request.method == 'POST': 
# 通过EmailPostForm表单类获取请求中的表单数据后保存到form中 
      form = EmailPostForm(request.POST) 
# 如果表单数据验证通过则发送邮件并将状态设置为已发送 
      if form.is_valid():
         cd = form.cleaned_data 
# 构建请求路径 
         post_url = request.build_absolute_uri(post.get_absolute_url()) 
# 构建邮件标题 
         subject = f"{cd['name']} recommends you read " \
                     f"{post.title}" 
# 构建邮件正文 
         message = f"Read {post.title} at {post_url}\n\n" \
                     f"{cd['name']}\'s comments: {cd['comments']}" 
# 发送邮件 
         send_mail(subject, message, 'wzrygfhx@sina.com',[cd['to']]) 
           
# 发送状态设置为真 
# 发送邮件，稍后完成 
# 发送状态设置为真 
         sent = True 
  else: 
# 如果表单数据验证未通过将表单设置为空 
      form = EmailPostForm() 
# 渲染分享文章模板，并将文章、表单、发送状态信息传递给文章分享模板 
  return render(request, 'blog/post/share.html', {'post': post,'form': form, 'sent': sent}) 

# Create your views here.

def post_search(request): 
  form = SearchForm() 
  query = None 
  results = [] 

 # 在最后增加了SearchForm

# 如果请求中有query字段则获取表单中的数据进行处理 
  if 'query' in request.GET: 
# 获取表单 
    form = SearchForm(request.GET) 
# 如果表单中的数据验证通过，即有效，则获取并处理 
  if form.is_valid(): 
# 获取搜索内容保存下来 
    query = form.cleaned_data['query'] 
# 根据标题和正文字段构建搜索向量并生成搜索字段，再根据搜索内容筛选出匹配内容
 
    results = Post.published.annotate( 
      search=SearchVector('title', 'body') 
      ).filter(search=query) 
# 将搜索结果渲染到搜索模板并返回 
  return render(request,  
'blog/post/search.html', { 
'form': form, 
'query': query, 
'results': results 
              })
